Bradley allan fisks



B. A. FISKE. ELECTRICAL RANGE FINDER.

(E30 Modal.)

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BRADLEY ALLAN FISKE, OF THE UNITED STATES NAVY.

mammal. woma -Flown.

' .mcmcxzrzox W m of yam; No. 444.917, datodizmuuy a, 1391, macaw ma 3m 2mm. am; He. 2mm. (2:; mm

To all whom it may concern:

Be in known that l, MRADLEYALLAX FISKE, of the United States Navy, have invented a 'uewand useful lmprm'emom in RoagwilndklUCllilg-My bearing in length a ratio Lathe angle includod between two lines of sight directed upon a distant object and simultaneously causing; a allsmrban'oe in an electrical balance including l'jll-ltl body in in: circuit proportional to thorwismnco of said my clonal portion and observing the difference in potential duo to said disturbance, 53ml also in an apparatus whereby my said method is carried into practical elfu'chwhich apparatus consists substantially in two bodies of conducting; material similarly disposed with reference to a prmlntcrmiuud base-line, allclazlw arms establishing and maintaining contact with said l!0l.ll(:-5,l1fldl.ll electrical measuringinstrmuon constructed i0 measure differences in olectricnl potential, said instalment bolng providml with an index and'a. scale marked in nulls of linear mmsuro, and the aforesaid parts being connected in electrical (:llClllt.

'll-o figure of the drawing rvpmsents a dingram illusii-niing the use of my improved mngwfimlma llol'm-ring lo the figure, lot All ho a lmsoline and '1 the position of a' listant object, the mngL-ol' whir-h AT is 10 be determined by n-monmnolry, In the triangle A'i'll,

' U AllXsin All'l' max m 7 lot (i and l) roprosezzt'uvo telescopes or alllndwmm pivotml who poinHA and Z3 and .wu'plng m'm' mcs E and i of cmulntlmg material, 1i) mill ares lmvin their extremi- Lol. tho tele- 001)": t, u: directed ugmn the point '1', assumng the position rupwsonled by C, dolled nuts flu-n,obviously, the angle (J'All is uguw! m Hm :mgglo fil'l'll nod the portion of he m1 2% imzhxlml holwooas llxo Ml$l0ll8 (f' and 5! "1' the wopn will :m-nsuro llwaoglo u- A'l'l;

v allcl.

In the foregoing formula the base-line AB is known by mewmremeniz and thoanglo ABT maybe observed, and if the angle A151 is, as shown in the figure. n ight angle, then tho sin AB'l becomes unlly. It remains, tharm formic fiml the angle ll'lB in order to de termine the (llxmnoe AT, so that is becomes necessarymprovideasimpleand rapid maohs of at onoodetarmining what. the angle ATS is. To this end lconneot 11m arcs E F of conductlog material in a Whoamtone bridge, the four mombers a! which are alxown respenlivclyab a, be 0!. in this bridge I conneemyjalmnom eter g in the zmml \vay md also thooatvery k, the terminals of tho baliery-wirabeing c011- neched to tho tolescopos at their pivotmints A B', so that the eircull; proceeds through the telescopes to the arcs, and then at tho are F diviilvs through the wires 5 d and at the are E divides through the wires-a. c It will be plain that when the two telescopes Cami I) Bland at right angles to the base line, and

hence parallel one to the olhor, the bridgn,

will balmica and the gzxlvanometer will BlJUW no defloctiom Tho line of sight of the two lolescopes than being parallel, the gailvanometor will than indicate infinite-mugs; and of ooumo this will be two no man?!- where the telescopes may be on thoirzfipectlvo arcs, so long as their lines of sigh Ii are relatively pm:-

greater as that arc inoruwscs, so that witho But i! one telescope be moved out of banal-y with constant oluolro-mutivo form it becomes pomiblo to deiormioo the extant of movement oi tho telescope i) bysimply oo- :serving llzolmiicatlon of tho galvunomolor. It will of comxo 11o obvloua llmt, as tho an glo between lilo posliious 0 and (1" of tho ielosoopo incronsvo, tho lungllx of the limo JL'l" will mmsmully ('lQUlUd-"i!., wllilu Llau lloll-sclion? fill"!l1!l';ll"lll"l!l will cooslzmzly lncream, so Llulb lln; gnlhuwmv'u" imliwmw lllilgtS Hurling l'mm infinity when tho galvmiunwlor alums 'no l lluzrtlun small margin 6 1.31; iniprdvgm have I urements m 110$, r'equ isbsaentia-Mheerrora hike-case Wham-i takmthe ungorrceted smear it. has sq smaiiitimt its sine v and by-Rmnkingiho contacts pmilbielerwci'a introduced. I w p n'BWitb myrungs-finder at abbot-t at the-'eifrtii'fi'flf qbservationare much greater than o! the instrument iv self,"gn ii1'pr-this.wprt;i.

l I "fail in potential nfail; p

when precise m'eas' above mentioned needcuik IS-inade smali ii-wiil n'ct be necessary m1- derordinary-conditiona m make both the cornotion-tor: sinaAB'lifandTtha correction for th'e -incmase of 'currxit du'oto the' objectboing: wig an angle tuft-haiimse-iine;jgbu sincetbese-iwoormczions aim in the onposim sensu I and madaapproxinmtei sulfloien'tiy accurate for practical purposesto equal, it; is

re idipgofi the gal vam been: assumed that the ang 0 ATS is Zimay be cousid'erbd as "'pmportionai totimangia, am aLsothaMhe 1daflectio z-of the; gaivauometar for'nnypugle vA'Ili is jjappmximazeiv pmportionni to, the current-strength in tiiu said circuit, and the nit length in the 4m:

infra ductingrbodybearing inlength a ratio to the m i'Mi-quickreading i rented upon a distant object. and'simuitane-- 'tionnl portion, and, second, reading directly mm the snitaiaiy-markediscaie of an eiecthe age 5235151355 as eqwmu msisa .in-dpterminiug a imotionalportidn of a con-f angle inciyuieql between twjq iln'esbf sight di reef/ed upon; a distant. objetaud aim ultane ousiy causing a diswrbanceiin an electrical balance :includiag said body. in 'itscircu proportional v 1:0 the resistance oizaaid mo Liana], portion und seqond, observing thaditferenca in tgmtiai in the said circuit due to saiddistur ace. 311;: Z i

2. The improvement. in m art or li'nding the range OI- a distant objecgwhich consists- :in determining-n fractional partion of a. mu ducting-body bearing in length a ratio to the angle included between two lines 05 sigh! Iii- 31' ously causing a disturbance in an electrical balance inciudingsaid body in its circuit proportional -10 t-ho maismnco of said (rm:- 

